<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script type="text/javascript">
			function fun1(i,j){
				return i-j;
			}
			
			var fun2 =function(i,j){
				return i-j
			}
			
			var fun3=new Function("i","j","return i-j");
		</script>
	</head>
	<body>
		<script type="text/javascript">
			var res1=fun1(2,1);console.log(res1);
			var res2=fun2(2,1);console.log(res2);
			var res3=fun3(2,1);console.log(res3);
		</script>
	</body>
</html>
